Number of days in the current month

NSDate *today = [NSDate date]; //Get a date object for today's date
NSCalendar *c = [NSCalendar currentCalendar];
NSRange days = [c rangeOfUnit:NSDayCalendarUnit 
                       inUnit:NSMonthCalendarUnit 
                      forDate:today];

NSLog(@"number of days: %d",  days.length);

Adding days to NSDate

int daysToAdd = 1;

NSDateComponents *components = [[[NSDateComponents alloc] init] autorelease];

[components setDay:daysToAdd];

// create a calendar

NSCalendar *gregorian = [[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar] autorelease];

NSDate *newDate = [gregorian dateByAddingComponents:components toDate:datePicker.date options:0];

Adding Days to an NSDate

iPhone SDK Tips & Tricks

NSDate *now = [NSDate date];

int daysToAdd = 50;

// set up date components

NSDateComponents *components = [[[NSDateComponents alloc] init] autorelease];

[components setDay:daysToAdd];

// create a calendar

NSCalendar *gregorian = [[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar] autorelease];

NSDate *newDate2 = [gregorian dateByAddingComponents:components toDate:now options:0];

NSLog(@"Clean: %@", newDate2);

Adding days to NSDate

iPhone SDK Tips & Tricks

NSDate *now = [NSDate date];
int daysToAdd = 50; // or 60 :-)

// set up date components
NSDateComponents *components = [[[NSDateComponents alloc] init] autorelease];
[components setDay:daysToAdd];

// create a calendar
NSCalendar *gregorian = [[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar] autorelease];

NSDate *newDate2 = [gregorian dateByAddingComponents:components toDate:now options:0];
NSLog(@"Clean: %@", newDate2);